Method of polymerizing cyclic olefins and vinyl olefins, copolymer produced by the method and political anisotropic film comprising the same

ABSTRACT

A method of copolymerizing cyclic olefins and polar vinyl olefins, a copolymer produced by the method, and an optical anisotropic film including the copolymer are provided. According to the copolymerization method, a cyclic olefin and a polar vinyl olefin can be effectively copolymerized using a catalyst system composed of a compound containing a group 13 element and a radical initiator. The resulting copolymer is transparent, and has high adhesion, thermal stability, optical anisotropy and strength, and a low dielectric constant. The optical film including the copolymer can be used as a plastic lens, a polarizer protective film, an adhesive film, and a compensation film, and in a LCD display.

CROSS-REFERENCE TO RELATED PATENT APPLICATION

This application claims the benefit of Korean Patent Application Nos.10-2004-0091568, filed on Nov. 10, 2004 and 10-2005-0106397, filed onNov. 8, 2005, in the Korean Intellectual Property Office, the disclosureof which is incorporated herein in its entirety by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method of copolymerizing cyclicolefins and vinyl olefins, a copolymer produced by the method, and anoptical anisotropic film comprising the same. More particularly, thepresent invention relates to a method of copolymerizing cyclic olefinsand vinyl olefins in a high yield, a high heat resistant copolymerproduced by the method, and an optical anisotropic film comprising thecopolymer.

2. Description of the Related Art

Inorganic materials such as silicon oxides or nitrides have been mainlyutilized in the information and electronic industries. Recent technicaldevelopments and demands for compact and high efficiency devices neednew high performance materials. In this respect, a great deal ofattention has been paid to polymers which have desirable physicochemicalproperties such as low dielectric constant and moisture absorption rate,high adhesion to metals, strength, thermal stability and transparency,and a high glass transition temperature (T_(g)>250° C.).

Examples of resins for optical components, which are generally used,include a methacrylic resin, polycarbonate, polyimide, and the like.However, these resins are not suitable for high performance opticalcomponents due to disadvantages such as low thermal stability, highbirefringence, and coloration.

Recently, polyacrylate, polyethersulfone (PES), polynorbornene (PNB),and cycloolefin copolymer (COC), which have a T_(g) of 100° C. orgreater, a transmittance of 90% or more, low birefringence, and a lowmoisture absorption property, appeared as alternative polymers. Thesepolymers consist of primarily a carbonyl group as a polar group and anaromatic or cyclic olefin portion as a non-polar group, and may furtherinclude fluorine (F) in order to improve physical properties such as aheat resistance, a refractive index, and a moisture absorption property.

PES is an amorphous and heat resistant engineering plastic whichincludes diaryl sulfone as a backbone and has a high Tg of approximately225° C. and a strong resistance to thermal aging. PNB is made ofnorbornene derivatives and has a high Tg of approximately 300° C., atransparency of 92% or greater, and a low birefringence. COC (or COP)consists of a cyclic olefin and an ethylene backbone and has a Tg of100-200° C., a high transparency, and a low birefringence, and can besubjected to extrusion and injection molding. And these have highertransparency, heat resistance, and chemical resistance and much lowerbirefringence and moisture absorption rate than conventional olefinpolymers. Thus, this polymer can be applied to various applications,e.g., optical components such as mobile phone camera lens, CD/DVDpick-up lens, LCD light guide panel and POFs (plastic optical fibers),electronic and information components such as capacitor films andlow-dielectrics, and medical components such as low-absorbent syringes,blister packagings, etc.

Meanwhile, polyacrylate has very high hardness and adhesion and hightransparency, and thus is widely used in an optical field such as glasssubstitutes.

Thus, when norbornene is copolymerized with acrylate, a new polymerhaving features to be applicable to broader field can be obtained.However, a polar vinyl olefin monomer is generally polymerized through aradical or anionic initiator, whereas a norbornene monomer isaddition-polymerized by a late transition metal catalyst such as Ni orPd. Due to such a contrary polymerization characteristic of the twomonomers, their direct copolymerization is difficult to carry out.

In the early days, norbornene and polar vinyl olefin were copolymerizedby radical polymerization, in which the content of norbornene in thecopolymer is very low (≦5.5% by weight) (Morris et al., U.S. Pat. No.3,536,681; Starmer et al., U.S. Pat. No. 3,679,490). Thereafter,copolymerization of norborene and acrylate using a palladium catalystwas reported, but a polymerization yield is low or it is difficult toobtain reproducible polymerization results (Goodall et al., U.S. Pat.No. 6,303,724; Sen et al., U.S. Pat. No. 6,111,041 and U.S. Pat. No.6,593,440).

Therefore, there has been a demand for a new method of producing acopolymer of norbornene and vinyl olefin with a high molecular weightand a high yield.

SUMMARY OF THE INVENTION

The present invention provides a method of copolymerizing cyclic olefinsand polar vinyl olefin monomers with a high molecular weight and a highyield.

The present invention also provides a copolymer, which has a lowdielectric constant, a high glass transition temperature, a high thermaland oxidative stability, toughness, a high chemical resistance andadhesion to metal, and thus can be used in electronic components.

The present invention also provides an optical film which has a hightransparency and controllable refractive index, and thus can be used asa polarizer protective film, an adhesive film, and an opticalanisotropic compensation film, and in a LCD display.

According to an aspect of the present invention, there is provided amethod of copolymerizing cyclic olefins and polar vinyl olefins, whichincludes:

contacting cyclic olefin monomers and polar vinyl olefin monomers with acatalyst system including:

i) a compound represented by formula (1) containing a group 13 element;and

ii) a radical initiator composed of an azo compound represented byformula (2) or a peroxide compound represented by formula (3):

M(R⁰)_(n1)(OR¹)_(n2)(X)_(n3)   (1)

where M is a group 13 element; O is an oxygen atom; each of n1, n2, andn3 is independently an integer of 0-3 and n1+n2+n3=3; each of R⁰ and R¹is independently a hydrogen atom; a linear or branched C₁₋₂₀ alkyl,alkenyl, or vinyl; a C₅₋₁₂ cycloalkyl optionally substituted by ahydrocarbon; a C₆₋₄₀ aryl optionally substituted by a hydrocarbon; or alinear or branched C₁₋₂₀ alkyl or aryl containing 1-10 hetreo atoms suchas N, O, and halogen atoms; and X is a halogen atom;

A₁-N═N-A₂   (2)

where N is a nitrogen atom; and each of A₁ and A₂ is independently ahydrogen atom; a linear or branched C₁₋₂₀ alkyl, alkoxy, alkenyl, orvinyl; a C₅₋₁₂ cycloalkyl optionally substituted by a hydrocarbon; aC₆₋₄₀ aryl optionally substituted by a hydrocarbon; or a linear orbranched C₁₋₂₀ alkyl, alkoxy, alkenyl, aryl, or cycloalkylheterocontaining a cyano group, a carbonyl group, a carboxylic group, an ethergroup, or an amide group;

B₁—O—O—B₂   (3)

where O is an oxygen atom; and each of B₁ and B₂ is independently ahydrogen atom; a linear or branched C₁₋₂₀ alkyl, alkoxy, alkenyl, orvinyl; a C₅₋₁₂ cycloalkyl optionally substituted by a hydrocarbon; aC₆₋₄₀ aryl optionally substituted by a hydrocarbon; or a linear orbranched C₁₋₂₀ alkyl, alkoxy, alkenyl, aryl, or cycloalkylheterocontaining a cyano group, a carbonyl group, a carboxylic group, an ethergroup, or an amide group.

According to another aspect of the present invention, there is provideda copolymer having good physical properties, produced by the abovemethod.

According to another aspect of the present invention, there is provideda polarizing protective film, an adhesive film, an optical anisotropicfilm, an optical compensation film, and a LCD display module.

When the copolymerization method according to an embodiment of thepresent invention is used, cyclic olefins and polar vinyl olefins can becopolymerized with a high yield using a catalyst system composed of acompound containing a group 13 element and a radical initiator. Thecopolymer produced by the method has good physical properties, includinghigh transparency, adhesion to metals or other polymers, thermalstability and strength, and a low dielectric constant. Thus, the opticalfilm including the copolymer can be used as a polarizer protective film,an adhesive film, and an anisotropic compensation film, and in a LCDdisplay module.

The inventors of the invention found that when cyclic olefin monomersand polar vinyl olefin monomers are contacted with a catalyst systemcomposed of a compound containing a group 13 element and an azo compound(or peroxide compound), a copolymer having high transparency and opticalanisotropy is obtained in a high yield.

BRIEF DESCRIPTION OF THE DRAWING

The above and other features and advantages of the present inventionwill become more apparent by describing in detail exemplary embodimentsthereof with reference to the attached drawings in which:

FIG. 1 is a ¹H NMR spectrum of a norbornene-methyl acrylate copolymer;

FIG. 2 is a ¹H NMR spectrum of a butyl norbornene-methyl acrylatecopolymer;

FIG. 3 is a ¹H NMR spectrum of a norbornene-methyl methacrylatecopolymer;

FIG. 4 is a ¹H NMR spectrum of a norbornene-methyl acrylate-styreneterpolymer;

FIG. 5 is a DSC (differential scanning calorimetry) thermodiagram of anorbornene-methyl acrylate copolymer;

FIG. 6 is a DSC thermodiagram of a norbornene-methyl methacrylatecopolymer; and

FIG. 7 is a DSC thermodiagram of a norbornene-methyl acrylate-styreneterpolymer.

DETAILED DESCRIPTION OF THE INVENTION

In the present invention, a cyclic olefin monomer, a polar vinyl olefinmonomer, and a catalyst are dissolved in a solvent and mixed topolymerize as in a conventional polymerization method. A catalyst systemto be contacted with the monomers includes a compound represented byformula (1), containing a group 13 element and a radical initiatorcomposed of an azo compound represented by formula (2) (or a peroxidecompound represented by formula (3)).

The cyclic olefin monomer is represented by formula (4):

where m is an integer of 0-4; R², R³, R⁴, and R⁵ may be a nonpolarfunctional group selected from a hydrogen atom, a halogen atom, a linearor branched C₁₋₂₀ alkyl, alkenyl, or vinyl, a C₅₋₁₂ cycloalkyloptionally substituted by a hydrocarbon, a C₅₋₄₀ aryl optionallysubstituted by a hydrocarbon, a C₇₋₁₅ aralkyl optionally substituted bya hydrocarbon, or a C₃₋₂₀ alkynyl; or a polar functional group selectedfrom the group consisting of —(CH₂)_(n)C(O)OR⁶, —(CH₂)_(n)OC(O)R⁶,—(CH₂)_(n)OC(O)OR⁶, —(CH₂)_(n)C(O)R⁶, —(CH₂)_(n)OR⁶, —(CH₂O)_(n)—OR⁶,—(CH₂)_(n)C(O)—O—C(O)R⁶, —(CH₂)_(n)C(O)NH₂, —(CH₂)_(n)C(O)NHR⁶,—(CH₂)_(n)C(O)N(R⁶)₂, —(CH₂)_(n)NH₂, —(CH₂)_(n)NHR⁶, —(CH₂)_(n)N(R⁶)₂,—(CH₂)_(n)OC(O)NH₂, —(CH₂)_(n)OC(O)NHR⁶, —(CH₂)_(n)OC(O)N(R⁶)₂,—(CH₂)_(n)C(O)Cl, —(CH₂)_(n)SR⁶, —(CH₂)_(n)SSR⁶, —(CH₂)_(n)SO₂R⁶,—(CH₂)_(n)SO₂R⁶, —(CH₂)_(n)OSO₂R⁶, —(CH₂)_(n)SO₃R⁶, —(CH₂)_(n)OSO₃R⁶,—(CH₂)_(n)B(R⁶)₂, —(CH₂)_(n)B(OR⁶)₂, —(CH₂)_(n)B(R⁶)(OR⁶),—(CH₂)_(n)N═C═S, —(CH₂)_(n)NCO, —(CH₂)_(n)N(R⁶)C(=O)R⁶,—(CH₂)_(n)N(R⁶)C(=O)(OR⁶), —(CH₂)_(n)CN, —(CH₂)_(n)NO₂,—(CH₂)_(n)P(R⁶)₂, —(CH₂)_(n)P(OR⁶)₂, —(CH₂)_(n)P(R⁶)(OR⁶),—(CH₂)_(n)P(=O)(R⁶)₂, —(CH₂)_(n)P(=O)(OR⁶)₂, and—(CH₂)_(n)P(=O)(R⁶)(OR⁶);

R⁶ is a hydrogen atom, a linear or branched C₁₋₂₀ alkyl, alkenyl, orvinyl, a C₅₋₁₂ cycloalkyl optionally substituted by a hydrocarbon, aC₆₋₄₀ aryl optionally substituted by a hydrocarbon, a C₇₋₁₅ aralkyloptionally substituted by a hydrocarbon, or a C₃₋₂₀ alkynyl; and,

n is an integer of 0-10; when R², R³, R⁴, and R⁵ are may be a polarfunctional group, a hydrogen atom, or a halogen atom, R² and R³, or R⁴and R⁵ can be connected to each other to form a C₁₋₁₀ alkylidene group,or R² or R³ can be connected to one of R⁴ and R⁵ to a saturated orunsaturated C₄₋₁₂ cyclic group or an C₆₋₁₇ aromatic ring compound.

The polar vinyl olefin monomer is represented by formula (5):

where at least one of R⁷ and R⁸ is a polar functional group selectedfrom the group consisting of —(CH₂)_(n)C(O)OR⁹, —(CH₂)_(n)OC(O)R⁹,—(CH₂)_(n)OC(O)OR⁹, —(CH₂)_(n)C(O)R⁹, —(CH₂)_(n)OR⁹, —(CH₂O)_(n)—OR⁹,—(CH₂)_(n)C(O)—O—C(O)R⁹, —(CH₂)_(n)C(O)NH₂, —(CH₂)_(n)C(O)NHR⁹,—(CH₂)_(n)C(O)N(R⁹)₂, —(CH₂)_(n)NH₂, —(CH₂)_(n)NHR⁹, —(CH₂)_(n)N(R⁹)₂,—(CH₂)_(n)OC(O)NH₂, —(CH₂)_(n)OC(O)NHR⁹, —(CH₂)_(n)OC(O)N(R⁹)₂,—(CH₂)_(n)C(O)Cl, —(CH₂)_(n)SR⁹, —(CH₂)_(n)SSR⁹, —(CH₂)_(n)SO₂R⁹,—(CH₂)_(n)SO₂R⁹, —(CH₂)_(n)OSO₂R⁹, —(CH₂)_(n)SO₃R⁹, —(CH₂)_(n)OSO₃R⁹,—(CH₂)_(n)B(R⁹)₂, —(CH₂)_(n)B(OR⁹)₂, —(CH₂)_(n)B(R⁹)(OR⁹),—(CH₂)_(n)N═C═S, —CH₂)_(n)NCO, —(CH₂)_(n)N(R⁹)C(=O)R⁹,—(CH₂)_(n)N(R⁹)C(=O)(OR⁹), —(CH₂)_(n)CN, —(CH₂)_(n)NO₂,—(CH₂)_(n)P(R⁹)₂, —(CH₂)_(n)P(OR⁹)₂, —(CH₂)_(n)P(R⁹)(OR⁹),—(CH₂)_(n)P(=O)(R⁹)₂, —(CH₂)_(n)P(=O)(OR⁹)₂, and—(CH₂)_(n)P(=O)(R⁹)(OR⁹); the remaining substituent is a hydrogen atom,a halogen atom, a linear or branched C₁₋₂₀ alkyl, alkenyl, or vinyl, aC₅₋₁₂ cycloalkyl optionally substituted by a hydrocarbon, a C₆₋₄₀ aryloptionally substituted by a hydrocarbon, a C₇₋₁₅ aralkyl optionallysubstituted by a hydrocarbon, or a C₃₋₂₀ alkynyl; n is an integer of0-10; and R⁹ is a hydrogen atom, a linear or branched C₁₋₂₀ alkyl,alkenyl, or vinyl, a C₅₋₁₂ cycloalkyl optionally substituted by ahydrocarbon, a C₆₋₄₀ aryl optionally substituted by a hydrocarbon, aC₇₋₁₅ aralkyl optionally substituted by a hydrocarbon, or a C₃₋₂₀alkynyl.

Meanwhile, the cyclic olefin monomer may be a non-polar cyclic olefinmonomer or a mixture of a polar cyclic olefin monomer and a cyclicolefin monomer.

The solvent used in the polymerization method may be an organic solventsuch as dichloromethane (CH₂Cl₂), dichloroethane (CH₂ClCH₂Cl),chloroform, benzene, toluene, or chlorobenzene (C₆H₅Cl). An amount ofthe solvent used is preferably 0.5-10 folds, more preferably 1-8 folds,most preferably 2-4 folds, relative to the volume of a monomer to beaddition polymerized. When the amount of the solvent is lower than 0.5folds, gel is formed and post-treatment become an indispensable. Whenthe amount of the solvent is higher than 10 folds, the polymerizationyield is low. Without such a solvent, bulk polymerization may be carriedout. In this case, the reaction solution is gellated or hardened duringthe polymerization, which can bring about an after-treatment problem.

A polymerization temperature may be in the range of 20-150° C., and maybe varied to change the polymerization conditions during the reaction.When the polymerization temperature is lower than 20° C., the catalystis not activated and the polymerization yield is low. When thepolymerization temperature is higher than 150° C., the catalyst may bedecomposed due to thermal instability.

In the polymerization method, the cyclic olefin monomer and the polarvinyl olefin monomer are not limited to only two monomers and mayinclude a combination of two cyclic olefin monomers, which havedifferent functional groups, and a polar vinyl olefin monomer, or acombination of two polar vinyl olefin monomers, which have differentfunctional groups, and a cyclic olefin monomer.

The copolymer may further include a non-polar vinyl olefin monomer inaddition to the cyclic olefin monomer and a polar vinyl monomer. Thenon-polar vinyl olefin monomer may be represented by formula (6):

where m is an integer of 0-4; and each of R¹⁰ and R¹¹ is a hydrogenatom, a halogen atom; a linear or branched C₁₋₂₀ alkyl, alkenyl, orvinyl; a C₅₋₁₂ cycloalkyl optionally substituted by a hydrocarbon; aC₆₋₄₀ aryl optionally substituted by a hydrocarbon; a C₇₋₁₅ aralkyloptionally substituted by a hydrocarbon; or a C₃₋₂₀ alkynyl.

In the polymerization method, it is preferable that the compoundrepresented by formula (1) containing a group 13 element is the compoundrepresented by formula (7), and the radical initiator is the azocompound represented by formula (2):

Al(R⁰)_(n1)(OR¹)_(n2)(X)_(n3)   (7)

where Al is an aluminium atom; O is an oxygen atom; each of n1, n2, andn3 is independently an integer of 0-3 and n1+n2+n3=3; each of R⁰ and R¹is independently a hydrogen atom; a linear or branched C₁₋₂₀ alkyl,alkenyl, or vinyl; a C_(b 5-12) cycloalkyl optionally substituted by ahydrocarbon; a C₆₋₄₀ aryl optionally substituted by a hydrocarbon; or alinear or branched C₁₋₂₀ alkyl or aryl containing 1-10 hetreo atoms suchas N, O, and halogen atoms; and X is a halogen atom;

A₁-N═N-A₂   (2)

where N is a nitrogen atom; and each of A₁ and A₂ is independently ahydrogen atom; a linear or branched C₁₋₂₀ alkyl, alkoxy, alkenyl, orvinyl; a C₅₋₁₂ cycloalkyl optionally substituted by a hydrocarbon; aC₆₋₄₀ aryl optionally substituted by a hydrocarbon; or a linear orbranched C₁₋₂₀ alkyl, alkoxy, alkenyl, aryl, or cycloalkylheterocontaining a cyano group, a carbonyl group, a carboxylic group, an ethergroup, or an amide group;

The copolymer produced by the method according to an embodiment of thepresent invention may include 0.1-99.9 mol % of a polar vinyl olefinmonomer and have a weight average molecular weight (Mw) of 10,000 orgreater. When the Mw of the copolymer is less than 10,000, it isdifficult to produce a film. The copolymer may have a glass transitiontemperature (Tg) of 100° C. or greater. When the Tg of the copolymer islower than 100° C., the thermal stability of film becomes poor.

The copolymer may be a copolymer blend which further includes at leastone of a cyclic olefin monomer, a polar vinyl olefin monomer, anon-polar vinyl olefin monomer, or a copolymer of a cyclic olefinmonomer and a polar vinyl olefin.

The copolymer produced in accordance with the method of the presentinvention is transparent, has sufficient adhesion to metals or polymerscontaining different polar functional groups, thermal stability andstrength, and exhibits a low dielectric constant sufficient to be usedas insulating electronic materials. The copolymer has a desirableadhesion to substrates of electronic components without requiring acoupling agent, and at the same time, a sufficient adhesion to metalsubstrates, e.g., Cu, Ag and Au. Further, the copolymer exhibits adesirable optical properties so that it can be used in electroniccomponents such integrated circuits (ICs), printed circuit boards,multichip modules, and the like.

Thus, the copolymer prepared by the present invention has hightransparency; molecular weight in the range of 10,000˜1,000,000 and theglass transition temperature in the range of 100˜200° C. which lead toafford to good moldability for a plastic lens. The plastic lens can beformed by various molding methods such as injection molding, compressionmolding, extrusion molding or injection compression molding. In theinjection compression molding, generally, the cylinder temperature is150 to 300° C. and the mold temperature is 50 to 150° C.

In addition, an optical film according to an embodiment of the presentinvention can be used as a polarizer protective film due to good heatresistance and strength, and has sufficient adhesion to polyvinylalcohol(PVA) to be attached to a polyvinylalcohol polarizer. Even when coronadischarge, glow discharge, flame treatment, acid treatment, alkalinetreatment, UV irradiation, or coating, if necessary, is performed on theoptical film, its transparency, etc. is not reduced.

The copolymer of the present embodiment can be used to produce anoptical anisotropic film capable of controlling a birefringence, whichcould not be produced with the conventional method. A conformationalunit of a general cyclic olefin has one or two stable rotation states,and thus can achieve an extended conformation such as polyimide having arigid phenyl ring as a backbone. When a monomer having a polarfunctional group is introduced into a norbornene-based polymer with anextended form, the interaction between molecules increases compared topolymers having compact conformations, and thus packing of molecules hasa directional order, thereby producing optical and electronicanisotropy.

The birefringence can be controlled according to the type and the amountof polar functional group in the copolymer of a cyclic olefin polymerand a polar vinyl olefin. In particular, the birefringence in adirection through the film thickness is easily controlled, and thus thepolymer of the present embodiment can be used to produce an opticalcompensation film for various modes of liquid crystal display (LCD).

The optical anisotropic film can be prepared by solution casting ormelting, or can be prepared with a blend of one or more copolymers ofcyclic olefins and polar vinyl olefins.

In order to prepare a film by solution casting, it is preferable tointroduce a copolymer of a cyclic olefin and a polar vinyl olefin in asolvent in amount of 5-95% by weight, and preferably 10-60% by weight,and stirring the mixture at room temperature. The viscosity of theprepared solution is preferably 100-10,000 cps, and more preferably300-8000 cps for solution casting. To improve mechanical strength, heatresistance, light resistance, and manipulability of the film, additivessuch as a plasticizer, an anti-deterioration agent, a UV stabilizer oran antistatic agent can be added.

The optical anisotropic film thus prepared has a retardation value(R_(th)) of 70 to 1000 nm, as defined by the following Equation 1:

R_(th)=Δ(n _(y) −n _(z))×d   (1)

where n_(y) is a refractive index of an in-plane fast axis measured at550 nm, n_(z) is a refractive index toward thickness direction measuredat 550 nm, and d is a film thickness.

The optical anisotropic film has clear picture quality at a wide viewingangle and can improve contrast when a driving cell is on or off, andthus can be used as an optical compensation film for LCD.

In particular, the optical anisotropic film has an optical axisperpendicular to a plate and meets a refractive index requirement ofn_(x)≡n_(y)>n_(z), in which n_(x) is a refractive index of an in-planeslow axis, n_(y) is a refractive index of an in-plane fast axis, andn_(z) is a refractive index toward thickness direction, and thus can beused as a negative C-plate type optical compensation film. Thus, theoptical anisotropic film can achieve a general liquid crystal mode ofLCD which meets a refractive index requirement of n_(x)≅n_(y)<n_(z), inwhich n_(x), n_(y), and n_(z) are as defined above, when a voltage is onor off.

Hereinafter, the present invention will be described in more detail withreference to the following Examples. However, these Examples are givenfor the purpose of illustration and are not to be construed as limitingthe scope of the invention.

EXAMPLES

In the following Preparation Examples and Examples, all operationshandling compounds sensitive to air or water were carried out usingstandard Schlenk technique or dry box technique. Nuclear magneticresonance spectra were obtained using a Bruker 300 spectrometer. ¹H NMRand ¹³C NMR were measured at 300 MHz and 75 MHz, respectively. Amolecular weight and a molecular weight distribution of a polymer weredetermined by gel permeation chromatography (GPC) using standardpolystyrene samples. Thermal analyses such as TGA (thermal gravimetricanalysis) and DSC (differential scanning calorimetry) were carried outusing TA Instrument (TGA 2050; heating rate 10K/min). Toluene wasdistilled and purified in potassium/benzophenone.

Preparation Example 1 Copolymerization of Norbornene and Methyl Acrylate

Norbornene (15.8 g, 168 mmol), methyl acrylate (10 mL, 112 mmol), andAIBN (2,2′-azobisisobutyronitrile) (0.037 g, 0.22 mmol) were chargedinto a 250 mL Schlenk flask and dissolved in 30 mL of toluene.Ethylaluminum sesquichloride (0.277 g, 1.12 mmol) was charged into a 100mL flask and dissolved in 20 mL of toluene. The toluene solution ofethylaluminum sesquichloride was slowly dropped to the 250 mL Schlenkflask at −70° C. The reaction temperature was raised to 45° C. whilestirring the mixture for 2 hours, and then the reaction was performed at45° C. for 12 hours. The reaction solution turned to light green incolor during the reaction. After the reaction was completed, thereaction solution was slowly dropped to 3000 cc of 5% v/v HCl-MeOH toprecipitate a white polymer, which was filtered through a glass filterand dried in a vacuum oven at 70° C. for 12 hours to obtain anorbornene-methyl acrylate copolymer (11.7 g: 58.2% by weight based onthe total weight of used monomers). The copolymer had a Tg of 140° C., amolecular weight (Mw) of 46,600, and Mw/Mn of 1.99.

¹H-NMR (300MHz in CDCl₃): 3.55 (br s, 3H), 2.5˜1.5 (br m, 13H)

Preparation Example 2 Copolymerization of Norbornene and Methyl Acrylate

Diethylaluminium chloride(1.36 g, 1.12 mmol) was used instead ofEthylaluminum sesquichloride used in Preparation Example 1. And,norbornene was copolymerized with methyl acrylate in the same way as thePreparation Example 1.

Polymerization yield was 12.1 g (60.2% by weight based on the totalweight of used monomers). The copolymer had a molecular weight (Mw) of68,000, and Mw/Mn of 2.12.

Preparation Example 3 Copolymerization of Norbornene and Methyl Acrylate

Diethylaluminium ethoxide(1.15 g, 1.12 mmol) was used instead ofEthylaluminum sesquichloride used in Preparation Example 1. And,norbornene was copolymerized with methyl acrylate in the same way as thePreparation Example 1.

Polymerization yield was 12.5 g (62.1% by weight based on the totalweight of used monomers). The copolymer had a molecular weight (Mw) of54,000, and Mw/Mn of 2.10.

Preparation Example 4 Copolymerization of Norbornene and Methyl Acrylate

Norbornene (15.8 g, 168 mmol), methyl acrylate (10 mL, 112 mmol), andDi-t-butylperoxide (0.32 g, 2.2 mmol) were charged into a 250 mL Schlenkflask and dissolved in 30 mL of toluene. Ethylaluminum sesquichloride(0.277 g, 1.12 mmol) was charged into a 100 mL flask and dissolved in 20mL of toluene. The toluene solution of ethylaluminum sesquichloride wasslowly dropped to the 250 mL Schlenk flask at −70°C. The reactiontemperature was raised to room temperature while stirring the mixturefor 2 hours, and then the reaction was performed at 80° C. for 12 hours.After the reaction was completed, the reaction solution was slowlydropped to 3000 cc of 5% v/v HCl-MeOH to precipitate a white polymer,which was filtered through a glass filter and dried in a vacuum oven at70° C. for 12hours to obtain a norbornene-methyl acrylate copolymer(10.5 g: 52.0% by weight based on the total weight of used monomers).The copolymer had a molecular weight (Mw) of 38,500, and Mw/Mn of 2.29.

Preparation Example 5 Copolymerization of 2-butylnorbornene and MethylAcrylate

2-butylnorbornene (16.8 g, 112 mmol), methyl acrylate (5 mL, 56 mmol),and AIBN (0.28 g, 1.68 mmol) were charged into a 250 mL Schlenk flaskand dissolved in 30 mL of toluene. Ethylaluminum sesquichloride (15.2 g;61.6 mmol) was charged into a 100 mL flask and dissolved in 20 mL oftoluene. The toluene solution of ethylaluminum sesquichloride was slowlydropped to the 250 mL Schlenk flask at −70° C. The reaction temperaturewas raised to room temperature while stirring the mixture for 2 hours,and then the reaction was performed at 65° C. for 12 hours. The reactionsolution turned to light green in color during the reaction. After thereaction was completed, the reaction solution was slowly dropped to 3000cc of 5% v/v HCl-MeOH to precipitate a white polymer, which was filteredthrough a glass filter and dried in a vacuum oven at 70° C. for 12 hoursto obtain a 2-butyl norbornene-methyl acrylate copolymer (5 g: 38.0% byweight based on the total weight of used monomers). The copolymer had aTg of 100° C., a molecular weight (Mw) of 8,180, and Mw/Mn of 3.2.

¹H-NMR (300 MHz in CDCl₃): 3.64 (br s, 3H), 2.5˜0.5 (br m, 21H)

Preparation Example 6 Copolymerization of Norbornene and MethylMethacrylate

Norbornene (8.8 g, 93 mmol), methyl methacrylate (5 mL, 47 mmol), andAIBN (0.23 g, 1.40 mmol) were charged into a 250 mL Schlenk flask anddissolved in 30 mL of toluene. Ethylaluminum sesquichloride (12.7 g,51.4 mmol) was charged into a 100 mL flask and dissolved in 20 mL oftoluene. The toluene solution of ethylaluminum sesquichloride was slowlydropped to the 250 mL Schlenk flask at −70° C. The reaction temperaturewas raised to room temperature while stirring the mixture for 2 hours,and then the reaction was performed at 65° C. for 12 hours. The reactionsolution turned to light green in color during the reaction. After thereaction was completed, the reaction solution was slowly dropped to 3000cc of 5% v/v HCl-MeOH to precipitate a white polymer, which was filteredthrough a glass filter and dried in a vacuum oven at 70° C. for 12 hoursto obtain a norbornene-methyl methacrylate copolymer (0.3 g: 3.0% byweight based on the total weight of used monomers). The copolymer had aTg of 167° C., a molecular weight (Mw) of 10,700, and Mw/Mn of 3.4.

¹H-NMR (300 MHz in CDCl₃): 3.60 (br s, 3H), 2.5˜0.8 (br m, 15H)

Preparation Example 7 Polymerization of Norbornene, Styrene, and MethylAcrylate

Norbornene (10.5 g, 112 mmol), styrene (0.6 g, 5.6 mmol), methylacrylate (5 mL, 56 mmol), and AIBN (0.028 g, 0.17 mmol) were chargedinto a 250 mL Schlenk flask and dissolved in 30 mL of toluene.Ethylaluminum sesquichloride (1.38 g, 5.6 mmol) was charged into a 100mL flask and dissolved in 20 mL of toluene. The toluene solution ofethylaluminum sesquichloride was slowly dropped to the 250 mL Schlenkflask at −70° C. The reaction temperature was raised to room temperaturewhile stirring the mixture for 2 hours, and then the reaction wasperformed at 65° C. for 12 hours. The reaction solution turned to lightgreen in color during the reaction. After the reaction was completed,the reaction solution was slowly dropped to 3000 cc of 5% v/v HCl-MeOHto precipitate a white polymer, which was filtered through a glassfilter and dried in a vacuum oven at 70° C. for 12 hours to obtain anorbornene-styrene-methyl acrylate terpolymer (7.1 g: 66.7% by weightbased on the total weight of used monomers). The copolymer had a Tg of120° C., a molecular weight (Mw) of 228,000, and Mw/Mn of 16.

¹H-NMR (300 MHz in CDCl₃): 7.4˜6.6 (br m, 5H), 3.8˜3.1 (br m, 3H),2.4˜0.6 (br m, 16H)

Examples 1-4: Preparation of Optical Anisotropic Film

Each of the polymers prepared in Preparation Examples 1, 5-7 was mixedwith a solvent to form a coating solution as shown in Table 1. Thecoating solutions were cast on a glass substrate using a knife coater ora bar coater, and then the substrate was dried at room temperature for 1hour and further dried under a nitrogen atmosphere at 100° C. for 18hours. The glass substrate was kept at −10° C. for 10 seconds and thefilm on the glass plate was peeled off with a knife to obtain a clearfilm having an uniform thickness. The thickness deviation of the filmwas less than 2%. The thickness and the light transmittance at 400-700nm of the obtained films were shown in Table 1

TABLE 1 Composition of film solution Physical properties of film PolymerSolvent Light (parts (parts Thickness transmittance by weight) byweight) (μm) (%) Example 1 Polymer THF 560 114 92 prepared inPreparation Example 1 Example 2 Polymer MC 360 and 120 92 prepared inTOLUENE 200 Preparation Example 5 Example 3 Polymer TOLUENE 550 118 90prepared in Preparation Example 6 Example 4 Polymer TOLUENE 400 103 91prepared in Preparation Example 7 In Table 1, THF is tetrahydrofuraneand MC is methylene chloride.

Measurement of Optical Anisotropy

For clear films produced in Examples 1-4, a refractive index n wasmeasured using an Abbe refractometer, an in-plane retardation value Rewas measured using an automatic birefringence analyzer (available fromOji Scientific Instrument; KOBRA-21 ADH), and a retardation value R_(θ)was measured when the angle between incident light and the film surfacewas 50° and a retardation value R_(th) between the direction through thefilm thickness and the in-plane x-axis was calculated using Equation 2:

$\begin{matrix}{R_{th} = {\frac{R_{\theta} \times \cos \; \theta_{f}}{\sin^{2}\theta_{f}}.}} & (2)\end{matrix}$

A refractive index difference (n_(x)−n_(y)) and a refractive indexdifference (n_(y)−n_(z)) were calculated by dividing R_(θ) and R_(th) bythe film thickness. (n_(x)−n_(y)), R_(θ), R_(th) and (n_(y)−n_(z)) ofeach clear film were indicated in Table 2.

TABLE 2 n (refractive index) (n_(x) − n_(y)) × 10³ R_(th)(nm/μm) (n_(y)− n_(z)) × 10³ Example 1 1.52 0.008 5.78 5.78 Example 2 1.50 0.009 2.132.13 Example 3 1.52 0.007 1.47 1.47 Example 4 1.51 0.013 3.59 3.59

When films were covered with a triacetate cellulose film havingn_(y)>n_(z), R_(θ) values of all cyclic olefin films increased, whichindicates that R_(th) of a cyclic olefin film is produced due to anegative birefringence (n_(y)>n_(z)) in a direction through the filmthickness.

Example 5 Surface Treatment and Lamination with Polyvinyl Alcohol (PVA)Polarization Film

The surface tension of the NB-MA copolymer film obtained from Example 1was determined by measuring the contact angle and using Equations 3 and4 (Wu, S.J. Polym. Sci. C Vol 34, P19, 1971):

$\begin{matrix}{\gamma_{S} = {\gamma_{SL} + {\gamma_{LV}\cos \; \theta}}} & (3) \\{\gamma_{SL} = {\gamma_{S} + \gamma_{LV} - {4\left( {\frac{\gamma_{LV}^{d}\gamma_{S}^{d}}{\gamma_{LV}^{d} + \gamma_{S}^{d}} + \frac{\gamma_{LV}^{p}\gamma_{S}^{p}}{\gamma_{LV}^{p} + \gamma_{S}^{p}}} \right)}}} & (4)\end{matrix}$

where γ_(S) is a surface tension of the film, γ_(LV) is a surfacetension of liquid, γ_(SL) is a interfacial tension between the film andliquid, cosθ is a contact angle, γ^(d) is a dispersion term of thesurface tension, and γ^(P) is a polar term of the surface tension.

When water was used, the contact angle was 74.3° and when methane wasused, the contact angle was 33.5°. A surface tension calculated fromthese values was 49.5 mN/m.

The NB-MA copolymer film was subjected three times to a corona treatmentat a current of 8 mA and a line speed of 6 m/min, and then the contactangle was measured. When water was used, the contact angle was 20.7° andwhen diode methane was used, the contact angle was 22°. A surfacetension calculated from these values was 76.9 mN/m.

Within 30 minutes after the corona treatment, the film was rolllaminated on a fully dried PVA polarization film in a 10% by weight PVAaqueous solution and dried at 80° C. for 10 minutes. Then, the PVApolarization plate on which the NB-MA copolymer film was laminatedexhibited excellent adhesion.

Example 6 Preparation of Plastic Lens

Each of the polymers prepared in Preparation Examples 1-4 was palletizedwith an extruder under nitrogen atmosphere. The obtained pellets wereinjection compression molded with a mold for a spectacle concave lens ata cylinder temperature of 200 to 300° C., at a mold temperature of 110°C. to obtain a lens. The obtained lens was tested under condition of 70°C., 95% RH relative humidity for 24 hrs to show a good appearance andmore than 90% light transmittance in the range of 400-700 nm.

According to the copolymerization method, a cyclic olefin and a polarvinyl olefin can be effectively copolymerized using a catalyst systemcomposed of a compound containing a group 13 element and a radicalinitiator. The resulting copolymer is transparent, has sufficientadhesion to metals or other polymers, thermal stability and strength,and exhibits a low dielectric constant sufficient to be used asinsulating electronic materials. Thus, the optical film including thecopolymer can be used as a polarizer protective film, an adhesive film,an anisotropic film, and a compensation film, and in a LCD display.

While the present invention has been particularly shown and describedwith reference to exemplary embodiments thereof, it will be understoodby those of ordinary skill in the art that various changes in form anddetails may be made therein without departing from the spirit and scopeof the present invention as defined by the following claims.

1-8. (canceled)
 9. A copolymer produced by the method of copolymerizingcyclic olefing and polar vinyl olefins, comprising: contacting a cyclicolefin monomer and a polar vinyl olefin monomer with a catalyst systemcomprising: i) a compound represented by formula (1) containing a group13 element; and ii) a radical initiator composed of an azo compoundrepresented by formula (2) or a peroxide compound represented by formula(3):M(R⁰)_(n1)(OR¹)_(n2)(X)_(n3)   (1) where M is a group 13 element; O isan oxygen atom; each of n1, n2, and n3 is independently an integer of0-3 and n1+n2+n3=3; each of R⁰ and R¹ is independently a hydrogen atom;a linear or branched C₁₋₂₀ alkyl alkenyl, or vinyl; a C₅-₁₂ cycloalkyloptionally substituted by a hydrocarbon; a C₆₋₄₀ aryl optionallysubstituted by a hydrocarbon; or a linear or branched C₁₋₂₀ alkyl oraryl containing 1-10 hetero atoms selected from a group consisting of N,O, and halogen atoms; and X is a halogen atom;A₁-N═N-A₂   (2) where N is a nitrogen atom, and each of A₁ and A₂ isindependently a hydrogen atom; a linear or branched C₁₋₂₀ alkyl, alkoxy,alkenyl, or vinyl; a C₅₋₁₂ cycloalkyl optionally substituted by ahydrocarbon; a C₆₋₄₀ aryl optionally substituted by a hydrocarbon; or alinear or branched C₁₋₂₀ alkyl, alkoxy, alkenyl, aryl, orcycloalkylhetero containing a cyano group, a carbonyl group, acarboxylic group, an ether group, or an amide group;B₁—O—O—B₂   (3) where O is an oxygen atom; and each of B₁ and B2 isindependently a hydrogen atom: a linear or branched C₁₋₂₀ alkyl, alkoxy,alkenyl, or vinyl; a C₅₋₁₂ cycloalkyl optionally substituted by ahydrocarbon; a C₆₋₄₀ aryl optionally substituted by a hydrocarbon; or alinear or branched C₁₋₂₀ alky, alkoxy, alkenyl, aryl, orcycloalkylhetero containing a cyano group, a carbonyl group, acarboxylic group, an ether group, or an amide group, wherein the cyclicolefin monomer is represented by formula (4):

where m is an integer of 0-4; R², R³, R⁴, and R⁵ may be a nonpolarfunctional group selected from a hydrogen atom, a halogen atom, a linearor branched C₁₋₂₀ alkyl, alkenyl, or vinyl, a C₅₋₁₂ cycloalkyloptionally substituted by a hydrocarbon, a C₆₋₄₀ aryl optionallysubstituted by a hydrocarbon, a C₇₋₁₅ aralkyl optionally substituted bya hydrocarbon, or a C₃₋₂₀ alkynyl; or a polar functional group selectedfrom the group consisting of —(CH₂)_(n)C(O)OR⁶, —(CH₂)_(n)OC(O)R⁶,—(CH₂)_(n)OC(O)OR⁶, —(CH₂)_(n)C(O)R⁶, —CH₂)_(n)OR⁶, —(CH₂)_(n)—OR⁶,—(CH₂)_(n)C(O)—O—C(O)R⁶, —(CH₂)_(n)C(O)NH₂, —(CH₂)_(n)C(O)NHR⁶,—(CH₂)_(n)C(O)N(R⁶)₂), —(CH₂)_(n)NH₂, —(CH₂)_(n)NHR⁶,—(CH₂)_(n)OC(O)NH₂, —(CH₂)_(n)OC(O)NHR⁶, —(CH₂)_(n)OC(O)N(R⁶)₂,—(CH₂)_(n)C(O)Cl, —(CH₂)_(n)SR⁶, —(CH₂)_(n)SSR⁶, —(CH₂)_(n)SO₂R⁶,—(CH₂)_(n)SO₂R⁶, —(CH₂)_(n)OSO₂R⁶, —(CH₂)_(n)SO₃R⁶, —(CH₂)_(n)OSO₃R⁶,—(CH₂)_(n)B(R⁶)₂, —(CH₂)_(n)B(OR⁶)₂, —(CH₂)_(n)B(R⁶)(OR⁶),—(CH₂)_(n)N═C═S, —(CH₂)_(n)NCO, —(CH₂)_(n)N(R⁶)C(=O)R⁶),(CH)₂)_(n)N(R⁶)C(=O)(OR⁶), —(CH₂)_(n)CN, —(CH₂)_(n)NO₂,—(CH₂)_(n)P(R⁶)₂, —(CH₂)_(n)P(OR⁶)(₂, —(CH₂)_(n)P(R⁶(OR⁶),—(CH₂)_(n)P(=O)(R)⁶)₂, —(CH₂)_(n)P(=O)(OR⁶)₂, and—(CH₂)_(n)P(=O)(R⁶)(OR⁶); R⁶ is a hydrogen atom, a linear or branchedC₁₋₂₀ alkyl, alkenyl, or vinyl, a C₅₋₁₂ cycloalkyl optionallysubstituted by a hydrocarbon, a C₆₋₄₀ aryl optionally substituted by ahydrocarbon, a C₇₋₁₅ aralkyl optionally substituted by a hydrocarbon, ora C₃₋₂₀ alkynyl; and, n is an integer of 0-10; when R², R³, R⁴, and R⁵are a polar functional group, a hydrogen atom, or a halogen atom, R² andR³, or R⁴ and R⁵ can be connected to each other to form a C₁₋₁₀alkylidene group, or R² or R³ can be connected to one of R⁴ and R⁵ toform a saturated or unsaturated C₄₋₁₂ cyclic group or an C₆₋₁₇ aromaticring compound.
 10. The copolymer of claim 9, which comprises
 0. 1-99.9mol % of a polar vinyl olefin monomer.
 11. The copolymer of claim 9,which has a weight average molecular weight (Mw) of 10,000 or greater.12. The copolymer of claim 9, which has a glass transition temperature(Tg) of 100° C. or greater.
 13. The copolymer of claim 9, which is acopolymer blend which further includes at least one of a cyclic olefinmonomer, a polar vinyl olefin monomer, a non-polar vinyl olefin monomer,or a copolymer of a cyclic olefin monomer and a polar vinyl olefin. 14.A polarizer protective film comprising the copolymer of claim
 9. 15. Anadhesive film comprising the copolymer of claim
 9. 16. An opticalanisotropic film comprising the copolymer of claim
 9. 17. The opticalanisotropic film of claim 16, which has a retardation value (R_(th)) of70 to 1000 nm, as defined by the following Equation 1:R_(th=Δ() n _(y) −n _(z))×d   (1) where n_(y) is a refractive index ofan in-plane fast axis measured at 550 nm, n_(z) is a refractive indextoward thickness direction measured at 550 nm, and d is a filmthickness.
 18. The optical anisotropic film of claim 16, which is anegative C-plate type optical compensation film for liquid crystaldisplay, satisfying a refractive index requirement of n_(x)≅n_(y)>n_(z),in which n_(x) is a refractive index of an in-plane slow axis, n_(y) isa refractive index of an in-plane fast axis, and n_(z) is a refractiveindex in a direction through the film thickness.
 19. A liquid crystaldisplay having a film comprising the copolymer of claim
 9. 20. A plasticlens comprising the copolymer of claim 9.